Field of the Invention
This invention relates to fiber optic and hybrid electro-optical cable assemblies. More particularly, the invention relates to cable assemblies adaptable to a variety of different remote radio unit conductor entry dimensional specifications.
Description of Related Art
The wireless communications industry is changing from traditional signal delivery from ground based transceivers delivering/receiving the RF signal to/from the antenna atop the radio tower via bulky/heavy/high material cost semi-rigid metal RF coaxial cable to optical signal delivery to a tower top mounted transceiver known as a remote radio unit (RRU) or remote radio head (RRH) with implementation of fiber to the antenna (FTTA) cabling.
As this area of the market is evolving quickly, many original equipment manufacturers (OEM) are providing different RRU/RRH with different termination requirements, requiring different fiber optic cable assemblies with different cable outer diameter (OD) and breakout lengths. For example, even when the RRU/RRH are from the same OEM, the required cable assemblies may have different requirements.
One requirement may be for a shorter breakout length wherein the connectorized breakout is captive and connectorized inside a small cavity of the RRU enclosure, for example, via a rubber gland that seals only against 5 mm OD cable. Alternatively, the OD may be, for example, 6 or 7 mm and the connector connectorized with another connector that is on an outside plate of the RRU. This larger diameter OD receiving connector may also seal against the OD of the larger diameter cable.
In regions where tropical birds such as cockatoos may be present, tower mounted cable assemblies may be provided with an armoring to resist crushing or tearing damage inflicted by the powerful beaks of these birds. Providing the cables with a crush sleeve of sufficient diameter to prevent a bird from taking the cable in its beak to apply a tear or crush force may be effective for preventing beak damage. However, large diameter cable sleeving may require elaborate and therefore expensive termination assemblies such as equipment specific collars and/or gaskets to avoid leaving a bare end of the crush sleeve open for the birds to engage.
Factory terminated hybrid cable assemblies are known. Furcation tubes may be applied to fibers and or fiber bundles stripped back from the cable end to protect the optical fibers from damage between the cable and the optical fiber termination. Optical fiber furcation tubes may consist of an inner polymer tube surrounded by a para-aramid synthetic fiber sheath, or a para-aramid synthetic fiber sheath alone.
Therefore, an object of the invention is to provide optical and/or electro-optical cable solutions that overcome deficiencies in the prior art.